CN104384465A - High-temperature superconducting magnetic stirrer used for continuous casting machine - Google Patents

Abstract

A high-temperature superconducting magnetic stirrer for a continuous casting machine, the high-temperature superconducting coil (1) is located in a liquid nitrogen container (3), and the liquid nitrogen container (3) is fixed to a vacuum container (4) by an epoxy resin rod (5) ), the vacuum vessel (4) is fixed on the turntable (7). Both ends of the infusion neck tube (6) are respectively connected to the inside of the liquid nitrogen container (3) and the outside of the vacuum container (4), and are sealed and welded to the liquid nitrogen container (3) and the vacuum container (4) respectively. By pouring liquid nitrogen into the liquid nitrogen container (3), the high-temperature superconducting coil (1) is cooled, and then the high-temperature superconducting coil (1) is charged, and then the superconducting switch (2) is closed, so that the high-temperature superconducting coil (1) Run without the power supply, and finally start the rotary table (7) to make the high magnetic field in the mold rotate, and the generated electromagnetic force drives the molten steel in the mold to rotate together to achieve the purpose of strong stirring.

Description

High temperature superconducting magnetic stirrer for continuous casting machine

technical field

The invention relates to a magnetic stirrer for a steelmaking continuous casting machine.

Background technique

The electromagnetic stirrer is used in the continuous casting machine to make the molten steel rotate, so that the ingredients added to the molten steel can be evenly distributed, and the quality of the cast slab can be improved. Due to the conductivity of molten steel, an eddy current is generated in the molten steel by applying a changing magnetic field on the molten steel, and the eddy current generates body force under the action of the magnetic field to drive the molten steel to move. There are two types of electromagnetic stirrers, one is the induction type, which generates an alternating magnetic field in the molten steel by applying an alternating current to the coil. This type of electromagnetic stirrer needs to pass a large current to the metal coil, so it needs Circulating water is used for cooling, and the water will have a certain corrosion effect on the coil, which increases the maintenance cost, and this type of electromagnetic stirrer consumes a lot of energy, which is not conducive to environmental protection; the other type is the dynamic type, that is, by making the external magnet move Therefore, a changing magnetic field is generated in the molten steel. This type of electromagnetic stirrer has low energy consumption and does not require a circulating cooling device, such as a permanent magnetic rotary stirrer. However, due to the limitation of the material properties of the permanent magnet, the magnetic field strength it generates is not high (1000-2000 Gauss), so in order to increase the rotational force of the molten steel, it is necessary to increase the rotational speed of the permanent magnet. High-speed rotation will increase energy consumption and wear of the equipment, which is not conducive to the long-term stable operation of the equipment.

Superconducting magnets can carry a large current unimpeded and generate a large magnetic field under certain temperature conditions, so they are widely used in applications that require high magnetic field strength. High-temperature superconducting magnets are a type of superconducting magnets with higher critical temperature, that is, lower temperature requirements and high stability. If the high temperature superconducting magnet is used instead of the permanent magnet in the permanent magnet rotary stirrer, a very high magnetic field will be generated in the crystallizer, resulting in a large rotational force, which can greatly reduce the rotational speed of the magnet.

Contents of the invention

The purpose of the present invention is to overcome the problems of low magnetic field intensity and high rotation speed of a permanent magnet rotary stirrer, and propose an electromagnetic stirrer using a high-temperature superconducting magnet. The invention adopts the superconducting magnet to replace the permanent magnet, which can increase the magnetic field intensity.

The high-temperature superconducting magnetic stirrer for a continuous casting machine of the present invention is composed of a high-temperature superconducting coil, a superconducting switch, a liquid nitrogen container, a vacuum container, an epoxy resin pull rod, an infusion neck tube, and a rotary table; the high-temperature superconducting The coil is located in the liquid nitrogen container, and the liquid nitrogen container is fixed in the vacuum container by an epoxy resin rod, thereby isolating the convective heat exchange between the liquid nitrogen and the room temperature. The vacuum container is fixed on the rotary table and can rotate together with the rotary table, and the rotary table is driven by a motor and other devices. The two ends of the infusion neck tube are respectively connected to the inside of the liquid nitrogen container and the outside of the vacuum container, and are respectively sealed and welded together with the liquid nitrogen container and the vacuum container to ensure the airtightness of the vacuum container.

The high-temperature superconducting coil can be made into a saddle shape, a racetrack shape, or a spiral tube shape, and the direction of the magnetic field at the center of the high-temperature superconducting coil should be perpendicular to the direction of the rotation axis of the stirrer.

The high-temperature superconducting magnetic stirrer for the continuous casting machine can form a unipolar magnetic field in the central crystallization area. At this time, a set of high-temperature superconducting coils is required, and a bipolar or multi-polar magnetic field can also be formed. Correspondingly, two sets of Or multiple sets of high-temperature superconducting coils, which are evenly distributed along the circumference; among them, the utilization rate of high-temperature superconducting coils is the highest in the case of a bipolar magnetic field, because the magnetic fields generated by two sets of high-temperature superconducting coils are linearly superimposed, and the utilization rate is the largest, while multiple sets of coils The generated magnetic field is vector addition, and the utilization rate is low.

The high-temperature superconducting magnetic stirrer used in the continuous casting machine first evacuates the vacuum container, and then pours liquid nitrogen into the liquid nitrogen container from the outside through the infusion neck to cool the high-temperature superconducting coil; then the high-temperature superconducting coil Power on, and close the superconducting switch to realize the operation of the high-temperature superconducting coil without the power supply; finally start the rotary table to drive the vacuum container and the high-temperature superconducting coil inside the vacuum container to rotate, thereby generating a rotating high magnetic field in the crystallizer. A large electromagnetic force is generated in the molten steel to drive the molten steel to rotate together to achieve the purpose of high-speed stirring.

Description of drawings

1 is a schematic diagram of a high-temperature superconducting magnetic stirrer for a continuous casting machine according to an embodiment of the present invention. In the figure: 1 high-temperature superconducting coil, 3 liquid nitrogen container, 4 vacuum container, 5 epoxy resin pull rod, 6 infusion neck tube, 7 Rotary table, 8 crystallizers;

Fig. 2 is a high temperature superconducting coil wiring diagram, in which: 1 high temperature superconducting coil, 2 superconducting switch, 9 DC power supply.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the high-temperature superconducting magnetic stirrer of the present invention is made up of high-temperature superconducting coil 1, liquid nitrogen container 3, vacuum container 4, epoxy resin rod 5, infusion neck tube 6, and rotary table 7; The high-temperature superconducting coil 1 is fixed in the liquid nitrogen container 3, and the liquid nitrogen container 3 is fastened in the vacuum container 4 by several epoxy resin rods 5, and the vacuum container 4 is fixed on the rotary table 7, The two ends of the infusion neck tube 6 are respectively connected to the inside of the liquid nitrogen container 3 and the outside of the vacuum container 4 for inputting liquid nitrogen into the liquid nitrogen container 3 from the outside, and the infusion neck tube 6 is connected to the liquid nitrogen container 3 and the vacuum container 4 respectively. The vacuum container 4 is sealed and welded together to ensure the airtightness of the vacuum container 4 .

The high-temperature superconducting coil 1 can be made into a saddle shape, a racetrack shape, or a spiral shape, etc. The high-temperature superconducting coil 1 is placed so that the direction of the magnetic field at the center of the high-temperature superconducting coil is perpendicular to the axis of rotation.

The high-temperature superconducting magnetic stirrer for the continuous casting machine can be made into a unipolar magnetic field, which requires a set of high-temperature superconducting coils 1, and can also be made into a bipolar or multi-pole magnetic field. Correspondingly, two or more sets are required High temperature superconducting coil 1.

The high-temperature superconducting magnetic stirrer for the continuous casting machine needs to evacuate the vacuum container 4 first, and then pour liquid nitrogen into the liquid nitrogen container 3 from the outside through the infusion neck 6 to cool the high-temperature superconducting coil 1 . Then the high-temperature superconducting coil 1 is energized by the DC power supply 9, and the high-temperature superconducting coil 1 is separated from the DC power supply 9 to run by closing the superconducting switch 2, as shown in Figure 2; finally, the rotary table 7 is started to drive the vacuum container 4 and the vacuum container 4. The high-temperature superconducting coil 1 inside rotates, thereby generating a rotating high magnetic field in the mold 8, generating a large electromagnetic force, and driving the molten steel in the mold to rotate together to achieve the purpose of high-speed stirring.

The continuous casting machine uses a high-temperature superconducting magnetic stirrer. When the liquid nitrogen is completely volatilized, the liquid nitrogen can be regularly replenished through the infusion neck tube 6 .

Claims (4)

1. a conticaster high-temperature superconductor magnetic stirring apparatus, it is characterized in that, described agitator is by high temperature superconductor coil (1), superconducting switch (2), liquid nitrogen container (3), vacuum tank (4), epoxy resin pull bar (5), transfusion neck tube (6), and turntable (7) composition; Described high temperature superconductor coil (1) is positioned at liquid nitrogen container (3), described liquid nitrogen container (3) is fixed in vacuum tank (4) by epoxy resin pull bar (5), vacuum tank (4) is fixed on turntable (7), the inside of connecting fluid nitrogen cascade (3) and the outside of vacuum tank (4) respectively, two ends of transfusion neck tube (6), and respectively together with liquid nitrogen container (3) and vacuum tank (4) seal welding.

2. according to conticaster high-temperature superconductor magnetic stirring apparatus according to claim 1, it is characterized in that, described high temperature superconductor coil (1) is the shape of a saddle or racetrack or screwed pipe shape, and the magnetic direction of high temperature superconductor coil (1) center is vertical direction.

3. according to conticaster high-temperature superconductor magnetic stirring apparatus according to claim 1, it is characterized in that, the described conticaster high-temperature superconductor magnetic stirring apparatus making magnetic field needs one group of high temperature superconductor coil (1); Make described conticaster high-temperature superconductor magnetic stirring apparatus that is bipolar or multipole magnetic field and need two or more sets high temperature superconductor coils (1).

4. according to conticaster high-temperature superconductor magnetic stirring apparatus according to claim 1, it is characterized in that, first described vacuum tank (4) is vacuumized, liquid nitrogen is poured into externally in liquid nitrogen container (3), cooling high-temperature superconducting coil (1) again by transfusion neck tube (6); Then be high temperature superconductor coil (1) energising, realize high temperature superconductor coil (1) by closed superconducting switch (2) and depart from power supply operation; Finally start turntable (7), the high temperature superconductor coil (1) of vacuum tank (4) and vacuum tank inside is driven to rotate, thus in crystallizer, produce the highfield of rotation, produce larger electromagnetic force, drive the molten steel in crystallizer to rotate together, reach the object of stirring at a high speed.